Conventional ink, either of the carbon pigment based or of the chemical reagent nonstaining type, is applied to the fingers of a person to be fingerprinted and the fingers are then pressed against a recording medium such as a fingerprint card. The ink is generally transferred to the finger from a flat surface which may be in the form of a glass plate or a pad impregnated with the ink. To provide a recorded image of the entire print area it is first necessary to roll the fingers, nail to nail, across the flat inking surface and then roll the fingers over the designated areas on the card. It is often difficult to maintain the same finger to inking surface pressure during the rolling motion resulting in an uneven coating of ink on the finger. The uneven coating is then transferred to the card resulting in a less than optimum print.
In addition to the uneven coating problem it may be difficult to roll the fingers over a flat inking surface especially where rolling the finger is difficult, such as where the person is deceased or has disabling arthritis.
One attempt at solving the above problem is disclosed in U.S. Pat. No. 3,971,335 ("'335 patent"). This patent teaches the use of a compressible roller arrangement in which ink from a reservoir is transferred to the surface of the inking roller via an ink transfer drum. The transfer drum is driven by an electric motor. The '335 arrangement is not only complex and expensive to manufacture (and maintain) but probably will not solve the problem of providing a uniform coating of ink on the finger. Uneven compression of the inking roller around the finger will result in an uneven distribution of ink. Ink transferred from a non-compressible surface generally provides higher quality prints.
There is a need for a simple and reliable fingerprint ink dispensing apparatus for applying ink to the finger in preparation for the taking of rolled fingerprints.